A nationwide outbreak of an intestinal illness caused by Cyclospora parasites has sickened more than 1,000 people in 40 states, including at least 14 people in Iowa.

Cyclosporiasis Cases as of Sept. 20, 2017

Cyclosporiasis is a disease caused by infection from Cyclospora cayetanensis parasites, which are spread through contaminated food or water. Public health officials have not identified a source of the infection for the current outbreak.

“At this time, no specific vehicle of interest has been identified, and investigations to identify a potential source, or sources, of infection are ongoing,” the CDC reported on Sept. 15. “It is too early to say whether cases of Cyclospora infection in different states are related to each other or to the same food item(s).”

Cyclospora infections can occur in many countries, but are more common in tropical and subtropical regions. It is not unusual, says the CDC, for cases to occur in the United States during the spring and summer. It is unusual to have more than 1,000 cases in one year.

In the four-month period from May 1 to Sept. 20, there have been 1,031 confirmed cases of cyclosporiasis in the United States. That compares to a total of 1,652 cases in the 15 years from 2000 to 2015.

The State Hygienic Laboratory was the first to identify bagged lettuce from Mexico as the source of a Cyclospora outbreak in 2013 that sickened 643 people in 25 states.

The CDC urges health care providers to “consider a diagnosis of cyclosporiasis in patients with prolonged or remitting-relapsing diarrheal illness. Testing for Cyclospora is not routinely done in most U.S. laboratories, even when stool is tested for parasites. Health care providers must specifically order testing for Cyclospora.”

Symptoms of cyclosporiasis – including profuse watery diarrhea, fatigue and low-grade fever – begin an average of seven days after ingestion of the parasite. Untreated cases of cyclosporiasis may last a few days or up to a month or longer, and can relapse.

Information about this outbreak and Cyclospora is available on the CDC website.